1. Field of Invention
The present invention relates to a door impact beam for a vehicle, and more particularly, to a door impact beam unit which is capable of significantly improving stability against door intrusion even in a 2-door vehicle by enhancing the stiffness of a door inner panel overlapping a B-pillar portion of a body frame and increasing an intrusion stopping force.
2. Description of Related Art
In general, a door includes a door impact beam provided to suppress a door from being intruded by a side impact.
The door impact beam is arranged across a door width in an internal space formed by a door outer panel and a door inner panel, and a mounting bracket welded and fixed to the panels is applied to both end portions of the door impact beam, thereby maintaining a fixed state.
The internal space is referred to as a safe space, because the internal space absorbs and reduces the deformation of the panels.
Typically, a door having a door impact beam installed therein has no difference in structure between a 4-door sedan vehicle and a 2-door coupe vehicle, but a body frame for providing an opening/closing support structure of the door has a large difference in structure between a 4-door sedan vehicle and a 2-door coupe vehicle.
FIG. 5A illustrates a body frame 100 applied to a 4-door sedan vehicle. Referring to FIG. 5A, body frame 100 includes an A pillar 101 which is closely attached to one side edge of a door 300 and forms a hinge coupling structure of the door and a B pillar 102 which is coupled to a door edge when door 300 is opened/closed.
An intrusion side portion 301 forming one side end of door 300 has an overlap section W which overlaps B pillar 102, and overlap section W overlaps the B pillar so as to cross the center line K-K of a B-pillar width B (overlap section A). Accordingly, intrusion side portion 301 may be more stably supported by B pillar 102.
FIG. 5B illustrates a body frame 200 applied to a 2-door coupe vehicle. Referring to FIG. 5B, body frame 200 includes an A pillar 201 which is closely attached to one side edge of door 300 and forms a hinge coupling structure of the door and a B pillar 202 which is coupled to a door edge when door 300 is opened/closed.
An intrusion side portion 302 forming one side end of door 300 has an overlap section W which overlaps B pillar 202, but overlap section W overlaps the B pillar so as not to cross the center line K-K of a B-pillar width B (overlap section a).
Typically, a door includes a door impact beam installed therein, regardless of whether the door is applied a 2-door coupe vehicle or 4-door sedan vehicle. Such a door impact beam relieves an impact and stops door intrusion, thereby more stably protecting passengers from the door intrusion regardless of vehicle types.
However, since overlap section a of the 2-door coupe vehicle is smaller than overlap section A of the 4-door sedan vehicle, the 2-door coupe vehicle is relatively vulnerable to door intrusion.
In particular, because of such a fundamental structural limit, an impact absorption operation through the door impact beam may not be satisfactorily performed.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.